1. Field of the Invention
The present invention relates to an extension of Ethernet protocol. More particularly, the present invention relates to a bridge-based radio access station backbone network structured by employing Ethernet technology and a method of treating signals thereof.
2. Description of the Related Art
Ethernet is a networking technology that was original designed for and most generally used with LANs (Local Area Networks). Over time, due to Ethernet's functionality and simple structure has caused Ethernet to become extremely popular, and Ethernet networking technology has extended its applicability for both very small LANs and WANs (Wide Area Networks).
FIG. 1 is an exemplary schematic diagram which illustrates the structure of a conventional WiBro (wireless broadband) radio access station backbone network. The WiBro in this example comprises a plurality of RASs (Radio Access Stations) 10 and a plurality of ACRs (Access Control Routers) 12. Besides, the WiBro network includes a home agent (not shown) for supporting the IP (Internet Protocol) mobility of a terminal, and an AAA server (Authentication, Authorization and Accounting) 14 for performing the authentication, authorization and accounting of the users and terminals in order to provide the network access and services for rightful persons.
The RASs 10 are allotted with respective service cells, wherein each cell provides communication services for a variety of equipment used by customers 11, such as a mobile communication terminal, PDA, and a notebook computer when any of the aforementioned examples are within the effective transmission area of a respective cell. The RAS 10 serves to mediate signals between the communications terminals 11 through a number of radio channels. In addition, the RAS 10 is connected through a wired channel to an ACR (Access Control Router) 12 forming an IP subnet. The signal wirelessly transmitted from the terminal 11 is packaged by the RAS 10 into an IP packet transferred to an upper ACR 12′, which switches it to another ACR 12″ adjacent to the target terminal according to the IP address thereof. Thus, the conventional RAS backbone network performs communication services by transmitting the IP packets to the target designated by an IP address.
However, the conventional RAS backbone network has been structured chiefly by employing 3tiered routers, which are relatively complicated in operation, resulting in ineffective network control. In addition, the 3-tiered routers also cause problems with delayed handover due to the problems that such routers have with handover operations.